1. Field of the Invention
The invention relates to a pin for quickly locking one element on another, and especially a wheel on a cycle frame or other machine.
2. Description of Background of Relevant Information
Locking pins of the aforementioned type are widely used, especially to very quickly mount and dismount a wheel on a frame. They are also used in the cycle industry, for example to immobilize the saddle bar in the saddle pillar.
The known wheel locking pins include a lengthy rod that extends through the wheel hub, with one rod end projecting on each side of the hub. One of the ends of the rod has a first tightening stop that is generally adjustable along the rod. This is usually a threaded end piece or a nut that is screwed at the threaded end of the rod.
The other end of the rod has a second movable tightening stop, whose movement along the rod is controlled by a lever journaled at the end of the axle and carrying an eccentric cam. The lever and its cam vary the distance separating the two stops. In particular, they make it possible to tighten at one time the two fixing lugs of the fork between the ends of the hub and the tightening stops.
The lever and its eccentric cam exert, at the level of the second stop, a movement with an axial component directed along the general direction of the rod, and a transverse component directed perpendicular to the axis of rotation of the lever.
Certain locking pins have a lever whose control lug is radially offset with respect to the axis of the rod. These pins have the disadvantage that the closing force of the lever is applied in a plane that passes next to the axis of the rod. In addition, the axle of the lever is subjected to torsional stress. Therefore it is necessary to provide it with ample dimensions. Overall, such a lever is not efficient.
For other locking pins, the axle of the lever has the shape of an eccentric cam that circulates in an oblong hole. There is a very high contact pressure between the cam and the wall of the oblong hole. It is therefore necessary to select highly resistant materials.
For yet other locking pins, the transverse component of the tightening movement radially offset the second stop with respect to the axis of the rod. Upon tightening, this movement causes either an offset of the rod, or a radial movement of the second stop with respect to the fixing lug of the fork against which it is pressed. At any event, in both cases, the position of the various elements is not perfectly controlled during tightening.
In addition, for most locking pins, tightening is carried out by rotating the lug of the lever over an angular amplitude of about 180 degrees. The 180 degree rotation is advantageous because it makes it possible to use low slope cams to perform the axial movement. This has the disadvantage that the lug of the lever has, with respect to the rod, a similar angular position in the closed position and in the open position. The specific shape of the lever is not always sufficient to differentiate these two positions, whereby running a possible risk of riding with a lever in the open position, when it is believed to be in the closed position.
The limiting position of the lever during opening is most often defined by an abutting of the eccentric in its housing. As a result, this position is not accurate, and in view of the different lever arm between the lever and the eccentric, premature wear and tear of the eccentric may occur if one has a tendency to strain at the lever during opening.